What is the evidence for electrical bone stimulation for fusion rate in patients after spinal surgery?
AMSTAR Rating
Summary
Patient Population:
This meta-analysis included nine randomized controlled trials (RCTs) and seven cohort studies. With a total of 2151 participants (Male=1116, Female=1035) with an average age of 51.6, the most common spinal fusion was performed in the lumbar spine. The most common fusion type was posterolateral, and interbody fusion.
Intervention:
Three different types of bone stimulators were used between the studies, including direct current (DC) stimulation, pulsed electromagnetic field (PEMF) stimulation, and capacitive coupling (CC) stimulation. Follow-ups with patients ranged between nine months and 49.3 months.
Comparison:
Control groups received placebo treatment. Roughly 1024 participants received placebo treatment, while 1127 participants received electrical stimulation.
Outcome:
Eleven studies used x-ray imaging to evaluate success of fusion, five used computed tomography (CT) scans, two used both x-ray and CT, one used magnetic resonance imaging (MRI), and one used patient-reported outcome measures including the Visual analogue scale (VAS), the Oswestry Disability Scale (ODI), and Short Form Health Survey (SF-36) questionnaire scores.
- Analysis of groups receiving electrical stimulation compared to control groups demonstrated statistically significant successful spinal fusion (OR 2.66 [95% CI 1.79–3.97]). Specifically, the RCT intervention groups compared to control groups scored an odds ratio (OR) of 2.10 (95% CI 1.35-6.75). Additionally, the average fusion rate for electrical stimulation groups was 86.8%, which is significantly greater than the control group’s rate of 73.7%. In the RCT group, intervention groups also showed higher rates of fusion (81.2%) compared to the control groups (68.2%).
- Groups receiving CC had the greatest improvement in spinal fusion rates compared to control groups (OR 3.44 [95% CI 1.75-6.75]). CC intervention in RCT groups compared to control also showed significant healing (OR 3.44 [95% CI 1.75-6.75]). DC showed 2.33 times greater fusion compared to controls (OR 2.33 [95% CI 1.37-3.96]). DC in RCT groups showed an OR of 1.50 (95% CI 0.84-2.69) demonstrating an insignificant fusion rate in intervention groups compared to controls. Overall PEMF demonstrated 2.60 times better healing compared to control (OR 2.60 [95% CI 1.75-6.75]). PEMF in RCT groups also demonstrated significant fusion in intervention groups compared to controls (OR 2.03 [95% CI 0.91-4.54]).
Guideline Recommendations
| Source | Recommendation |
|---|---|
| American Association of Neurological Surgeons (AANS) (2014) | Support use in HIGH RISK for Non-union |
| North American Spine Society (NASS) (2016) | Limited Support in HIGH RISK |
Outcomes Assessed
- Benefit
- Harm
- Inconclusive
Healing (Fusion)
HIGH RISK
LOW/NORMAL RISK
Pain
Short term
Long term
Function
Short term
Long term
Relevant Clinical Info
Foley KT, Mroz TE, Arnold PM, Chandler HC Jr, Dixon RA, Girasole GJ, Renkens KL Jr, Riew KD, Sasso RC, Smith RC, Tung H, Wecht DA, Whiting DM. Randomized, prospective, and controlled clinical trial of pulsed electromagnetic field stimulation for cervical fusion. Spine J. 2008 May-Jun;8(3):436-42. doi: 10.1016/j.spinee.2007.06.006. Epub 2007 Jul 17. PMID: 17983841.
Foley et al. (2008) was the largest RCT included in this meta-analysis, with 323 participants (Male=175, Female=148). Researchers examined the effect of PEMF stimulation compared to no stimulation in the healing of patients with risk factors for nonunion after anterior cervical discectomy and fusion (ACDF) surgery. Using neurological assessment, VAS for shoulder and arm pain, 12-Item Short Form Survey (SF-12) scores, neck disability index (NDI), and radiographs (anteroposterior, lateral, and flexion-extension views) for outcome measure assessment, it was determined that PEMF was an effective and safe intervention. At 6 weeks, the PEMF group had significantly higher rates of fusion at 83.6% compared to control group fusion at 68.6% (p=0.0065). At 12 months, while the PEMF group still had higher fusion rates (92.8%) compared to the control group (86.7%), the results were not statistically significant (p=0.1129). Researchers also found that, while there were improvements in all outcome measures for both groups, there were no significant differences between intervention and control groups at 6 weeks or 12 months in regard to VAS, NDI, or SF-12 score. Additionally, there was no statistically significant difference between adverse events experienced in intervention and control groups.
Participant Information
of participants
were Male
The sample size was 2151
Mean age of 51.6 years.
There were 16 studies used.
